Exposure device

ABSTRACT

A light beam emitted from a light source passes through a spatial light modulation device, at which a plurality of unit elements for respectively modulating incident light beam are two-dimensionally arrayed, and a microlens array, at which a plurality of microlenses corresponding to the unit elements are arrayed, and is focused on an exposure surface. A four-part detector, which is structured by four diodes, is disposed on the exposure surface so as to correspond to four pixels which are present at one corner of the exposure area. Relative mispositioning between the spatial light modulation device and the microlens array generates a difference in respective detection signals of the four diodes. Thus, an offset between the spatial light modulation device and the microlenses can be detected. Positional adjustment of the microlens array is performed on the basis of a detected offset amount.

CROSS-REFERENCE TO RELATED APPLICATION

This is a continuation of application Ser. No. 10/807,310 filed Mar. 24,2004, which claims priority under 35 USC 119 from Japanese PatentApplication No. 2003-83608. The entire disclosure of the priorapplication, application Ser. No. 10/807,310 is hereby incorporated byreference.

This application claims priority under 35 USC 119 from Japanese PatentApplication No. 2003-83608, the disclosure of which is incorporated byreference herein.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an exposure device, and particularly toan exposure device which exposes a photosensitive material with a lightbeam which is modulated by a spatial light modulation device inaccordance with image data.

2. Description of the Related Art

Heretofore, various exposure devices have been proposed which carry outimage exposure with light beams which have been modulated, using spatiallight modulation devices, in accordance with image data, such as, forexample, exposure devices for photo masks which are employed in liquidcrystal fabrication devices, exposure devices for printing platefabrication and the like.

An exposure device which uses a digital micromirror device (DMD) as aspatial light modulation device has been structured by, for example, alight source 1, a lens system 2, a DMD 3 and lens systems 4 and 6, asshown in FIG. 9A. The light source 1 irradiates laser light. The lenssystem 2 collimates the laser light irradiated from the light source 1.The DMD 3 is disposed substantially at a focusing position of the lenssystem 2. The lens systems 4 and 6 focus the laser light, which has beenreflected from the DMD 3, onto a scanning surface 5. The DMD is a mirrordevice in which numerous micromirrors, which alter angles of reflectionsurfaces thereof in accordance with control signals, are arrangedtwo-dimensionally on a semiconductor support of silicon or the like. Inthis exposure device, the laser light is modulated by ON-OFF control ofeach of the micromirrors of the DMD 3 from an unillustrated controlapparatus, by control signals which are generated in accordance withimage data or the like, and image exposure is carried out with themodulated laser light. Note that FIG. 9A is an unfolded schematic viewalong an optical axis.

In such an exposure device, for example, with the goal of reducing spotdiameter and raising resolution, a microlens array (MLA) 8 may bedisposed so as to correspond with an image of the DMD 3, as shown inFIG. 9B, and image exposure with a high resolution may be carried out.Note that, in FIG. 9B, the laser light that has been irradiated from thelight source 1 and collimated at the lens system 2 is reflected at atotal internal reflection (TIR) prism and illuminated to the DMD 3.Further, the laser light that has been reflected at the DMD 3 passesthrough the TIR prism and is incident at the lens system 4.

However, in an exposure device which is equipped with a confocal opticalsystem which condenses light reflected from a DMD by lenses of amicrolens array (MLA), passes the light through apertures and focusesthe light, even if optical axis adjustment is carried out at a time ofassembly, relative mispositioning between structural members arisesbecause of thermal expansion of the structural members, chronologicaldevelopment of residual stresses in the structural members and the like,and there is a problem in that images on the DMD are not accuratelyprojected to a focusing plane. Further, as a result thereof, there areproblems in the exposure device in that utilization efficiency of lightfalls, focusing positions are shifted, and light spills over intoneighboring pixels and causes a deterioration in resolution.

SUMMARY OF THE INVENTION

The present invention has been devised in order to solve problems withthe conventional technology described above, and an object of thepresent invention is to provide an exposure device which can accuratelyproject an image of a spatial light modulation device at a focusingplane.

In order to achieve the object described above, an exposure device of afirst aspect of the present invention includes: a light source whichemits a light beam for exposure; a spatial light modulation device atwhich a plurality of modulation elements, which respectively changelight modulation states thereof in accordance with control signals, aretwo-dimensionally arranged, the spatial light modulation device beingfor modulating the light beam, which is incident at the plurality ofmodulation elements from the light source, at each of the modulationelements; a microlens array at which a plurality of microlenses aretwo-dimensionally arranged with a pitch corresponding to the pluralityof modulation elements, the microlens array being for condensing lightbeams, which have been modulated by the modulation elements, at therespective microlenses; a shift amount detection section for detectingan offset amount of relative positions of the light beams which havebeen modulated by the modulation elements and the correspondingmicrolenses; and a position adjustment section which finely adjustsposition of at least one of the spatial light modulation device and themicrolens array on the basis of the detected offset amount.

In the exposure device of the aspect of the present invention describedabove, the light beam that is incident at the spatial light modulationdevice from the light source is modulated by the modulation elements ofthe spatial light modulation device, and the light beams that have beenmodulated are condensed at the respective microlenses of the microlensarray. At this time, relative mispositioning between the spatial lightmodulation device and the microlens array occurs because of thermalexpansion, chronological development of residual stresses and the like.Accordingly, an offset amount of relative positions of the light beamsthat have been modulated by the respective modulation elements of thespatial light modulation device and the corresponding microlenses isdetected by the shift amount detection section. Hence, the position ofthe at least one of the spatial light modulation device and themicrolens array is finely adjusted by the position adjustment section onthe basis of the detected offset amount. Thus, the light beams that havebeen modulated by the respective modulation elements are properlyincident at the corresponding microlenses, and an image of the spatiallight modulation device is accurately projected at the focusing plane.

In the exposure device described above, it is preferable if the positionadjustment section finely adjusts the position of the at least one ofthe spatial light modulation device and the microlens array, on thebasis of the detected offset amount, such that the offset amount isreduced. More specifically, it is preferable to finely adjust theposition of the at least one of the spatial light modulation device andthe microlens array such that the offset amount of the relativepositions of the light beams modulated by the modulation elements andthe corresponding microlenses, which is detected at the shift amountdetection section, is not more than a predetermined amount.

Further, in the exposure device described above, a focusing opticalsystem may be provided which focuses the light beams that have beenmodulated by the modulation elements so as to correspond with themicrolenses. In a case in which such a focusing optical system isprovided, the position of at least one of the spatial light modulationdevice, the microlens array and an optical member which structures thefocusing optical system is finely adjusted. Of these structural members,if a position of a member whose sensitivity with respect to optical axisshifting is lower is adjusted, optical axis adjustment is easier.

In this case too, it is preferable if the position adjustment sectionfinely adjusts the position of the at least one of the spatial lightmodulation device, the microlens array and the optical memberstructuring the focusing optical system, on the basis of the detectedoffset amount, such that the offset amount is reduced. Morespecifically, it is preferable to finely adjust the position of the atleast one of the spatial light modulation device, the microlens arrayand the optical member structuring the focusing optical system such thatthe offset amount of the relative positions of the light beams modulatedby the modulation elements and the corresponding microlenses, which isdetected at the shift amount detection section, is not more than apredetermined amount.

Further, a shift amount detection section which includes a plurality oflight detection elements, which correspond, respectively, to a mutuallyadjacent plurality of the modulation elements, and a calculationsection, which calculates the offset amount of the light beams whichhave been modulated by the modulation elements and the correspondingmicrolenses on the basis of detection signals from the plurality oflight detection elements, can be used as the shift amount detectionsection. As the light detection elements, beside photodiodes,phototransistors, a CCD (charge coupled device) or the like can beemployed.

For example, a four-part (fourfold) detector may be employed whichincludes four photodiodes, which correspond, respectively, to four ofthe modulation elements which are arranged in a matrix form, and acalculation section which calculates, on the basis of detection signalsfrom the four photodiodes, a row direction offset amount and a columndirection offset amount of the light beams modulated by these modulationelements and the corresponding microlenses.

Further still, a trimming mechanism which utilizes piezoelectricelements may be employed as the position adjustment section.

An exposure device of one other aspect of the present inventionincludes: a light source which emits a light beam; a spatial lightmodulation device including a plurality of unit elements which arearranged two-dimensionally, the spatial light modulation device beingfor modulating the light beam, which is incident at the plurality ofunit elements, at each of the unit elements in accordance with controlsignals which are inputted to the spatial light modulation device; amicrolens array including microlenses which are arranged to correspondto the plurality of unit elements and which respectively condense lightbeams, which have been modulated by the unit elements; a displacementdetection section for detecting displacement of a relative position ofat least one of the plurality of unit elements and at least one of theplurality of microlenses corresponding to the at least one unit elementfrom a predetermined relative position; and a position adjustmentsection which finely adjusts position of at least one of the spatiallight modulation device and the microlens array on the basis of thedetected displacement.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic view showing structure of an exposure device of apresent embodiment.

FIG. 2A is a plan view showing an exposure area formed on a stage.

FIG. 2B is a plan view showing an arrangement of a four-part detector.

FIG. 3A is a diagram showing four pixels which light up during detectionof mispositioning.

FIG. 3B is an explanatory view of a procedure for detectingmispositioning with the four-part detector.

FIG. 4A is a diagram showing a situation in which modulation elements ofa DMD conform with positions of microlenses of a microlens array.

FIG. 4B is a diagram showing a situation in which the modulationelements of the DMD do not conform with the positions of the microlensesof the microlens array.

FIG. 5 is a flowchart showing a control routine when correction ofmispositioning of a beam is carried out.

FIG. 6 is a plan view showing another arrangement of a four-partdetector.

FIG. 7 is a diagram showing pixels which light up when an offset amountin an X direction and an offset amount in a Y direction are to bedetected separately.

FIG. 8 is a diagram showing an example in which the four-part detectorhas a structure which enables insertion and withdrawal.

FIG. 9A is a side view showing structure of a conventional exposure headalong an optical axis thereof.

FIG. 9B is a side view showing structure of a conventional exposure headalong an optical axis thereof.

DETAILED DESCRIPTION OF THE INVENTION

Below, details of an embodiment of the present invention will bedescribed with reference to the drawings.

Structure of Exposure Device

As shown in FIG. 1, the exposure device relating to the presentembodiment is equipped with a digital micromirror device (DMD) 10, whichserves as a spatial light modulation device for modulating an incidentlight beam at each of pixels in accordance with image data. A lightsource 12, which illuminates the DMD 10, is disposed at a lightincidence side of the DMD 10. Meanwhile, at a light reflection side ofthe DMD 10, an enlargement lens system 14 and a magnification adjustmentlens 16 are disposed in that order from an upstream side. Theenlargement lens system 14 enlarges a DMD image which has been reflectedfrom the DMD 10, and the magnification adjustment lens 16 adjusts afocusing magnification.

A microlens array 18 is disposed at a position at which the DMD image isfocused by the magnification adjustment lens 16. Microlenses thereof aredistributed to correspond to respective modulation elements of the DMD10. A focusing lens system 20 is disposed at a light emission side ofthe microlens array 18 such that the DMD 10 and an exposure surface havea conjugative relationship.

A stage 24, on which a light-sensitive member 22 is placed, is disposedat a light emission side of the focusing lens system 20. The stage 24 isstructured to be movable in three directions, an X direction, a Ydirection, and a Z direction which intersects an X-Y plane. A four-partdetector 26 is disposed on the stage 24, at the same height as anexposure surface of the light-sensitive member 22.

The DMD 10 is connected to a controller 30 via a driving section 28,which drives the respective micromirrors. The controller 30 isconstituted by a computer which is equipped with a CPU, ROM, RAM,memory, input/output devices such as a monitor, a keyboard and the like,and the like.

A trimming mechanism 32, which utilizes piezoelectric elements, ismounted at the magnification adjustment lens 16. This trimming mechanism32 is connected to the controller 30 via a driving section 34. Aposition detection sensor 36, which detects position of themagnification adjustment lens 16, is disposed in a vicinity of themagnification adjustment lens 16. The trimming mechanism 32 finelyadjusts the position of the magnification adjustment lens 16 in the Xand Y directions on the basis of detection signals from the positiondetection sensor 36.

A trimming mechanism 38 which utilizes piezoelectric elements is mountedat the microlens array 18, similarly to the magnification adjustmentlens 16. This trimming mechanism 38 is connected to the controller 30via a driving section 40. A position detection sensor 42, which detectsposition of the microlens array 18, is disposed in a vicinity of themicrolens array 18. The trimming mechanism 38 finely adjusts theposition of the microlens array 18 in the X and Y directions on thebasis of detection signals from the position detection sensor 42.

Here, it is required that the modulation elements of the DMD 10 and themicrolenses of the microlens array 18 have a one-to-one correspondence,and a magnification rate of the enlargement lens system 14 is specifiedsuch that pixel pitches of the modulation elements and the microlensescoincide. However, the magnification rate of this lens will have anerror of 1 or 2%, due to irregularities in curvatures of the lens,inter-surface spacings and refraction rates, and the like. Because themagnification adjustment lens 16 is disposed in addition to theenlargement lens system 14, a spacing between the enlargement lenssystem 14 and the magnification adjustment lens 16 can be adjusted.Thus, errors due to lens magnification rates can be corrected for, and alens magnification rate can be adjusted to accord with a design value.

The stage 24 is connected to the controller 30 via a driving section 44.This driving section 44 drives the stage 24 in accordance with controlsignals from the controller 30. The four-part detector 26 disposed onthe stage 24 is also connected to the controller 30, and detectionsignals from the four-part detector 26 are inputted to the controller30.

Next, an exposure operation of the exposure device shown in FIG. 1 willbe described. When image data is inputted to the controller 30, thecontroller 30 generates control signals to control driving of themicromirrors of the DMD 10, based on the inputted image data. On thebasis of these control signals, the driving section 28 changes angles ofreflection surfaces of the micromirrors of the DMD 10.

Illumination light that is irradiated at the DMD 10 from the lightsource 12 is reflected in predetermined directions in accordance withthe angles of the reflection surfaces of the micromirrors, and is thusmodulated. The modulated light is enlarged by the enlargement lenssystem 14. Accordingly, a size of pixel spots of the DMD 10 on theexposure surface is enlarged, and a pitch of the pixel spots is alsoenlarged.

A focusing magnification rate of the light that has been enlarged by theenlargement lens system 14 is finely adjusted by the magnificationadjustment lens 16. The light whose magnification rate has been thusadjusted is incident at the respective microlenses provided at themicrolens array 18, and the enlarged DMD images are contracted again.Here, all flux of the light is incident on the microlens array 18. Thelight that has been condensed at the microlens array 18 is incident atthe focusing lens system 20, and an image of the DMD 10 is focused onthe exposure surface of the light-sensitive member 22 by the focusinglens system 20.

Four-Part Detector

When the stage 24 is disposed at a reference position, the four-art(fourfold) detector 26 is disposed at at least one of four corners A, B,C and D of a rectangular exposure area 46 which is formed on the stage24, as shown in FIG. 2A. The exposure area 46 is constituted by a largenumber of pixels, which correspond to the respective modulation elementsof the DMD 10.

For example, as shown in FIG. 2B, in a case in which the four-artdetector 26 is disposed at corner A, the four-art detector 26 isdisposed such that four pixels 48 ₁, 48 ₂, 48 ₃ and 48 ₄ correspond tofour diodes 26 ₁, 26 ₂, 26 ₃ and 26 ₄, respectively, of the four-partdetector 26. The four pixels 48 ₁, 48 ₂, 48 ₃ and 48 ₄ (which are pixelsof exposed images) are present at corner A of the exposure area 46 andare mutually adjacent.

With a four-part detector with a size of around 1.5 mm by 2.0 mm, if aspacing between neighboring diodes is approximately 15 μm and a spacingbetween neighboring pixels of an exposed image is approximately 70 μm,then it is possible for the four-part detector 26 to be disposed with apositional accuracy with respect to the four pixels of ±20 μm.

Next, a method for using the four-part detector 26 to detect relativemispositioning of the DMD 10 and the microlens array 18 will bedescribed. First, as shown in FIG. 3A, the four modulation elements ofthe DMD 10 that correspond to the four pixels 48 ₁, 48 ₂, 48 ₃ and 48 ₄which are present at corner A of the exposure area 46 are lit up. Thatis, the modulation elements modulate the light beam such that those fourpixels could be exposed.

As shown in FIG. 3B, if output signals of the four diodes 26 ₁, 26 ₂, 26₃ and 26 ₄ corresponding to the four pixels are, respectively, P₁, P₂,P₃ and P₄, then, in a case in which there is relative mispositioningbetween the DMD 10 and the microlens array 18, values of the outputsignals P₁, P₂, P₃ and P₄ will be out of balance. For example, in thisexample only the value of P₄ is large.

Factors which cause imbalances will be briefly described. In a case inwhich, as shown in FIG. 4A, the light beams that are modulated by themodulation elements of the DMD 10 coincide with the positions of thecorresponding microlenses of the microlens array 18, the beams that areincident on the microlenses will be focused at predetermined positionsof the exposure surface. In contrast, if, as shown in FIG. 4B, themicrolens array 18 is offset in the direction of arrow A, portions ofbeams corresponding to neighboring modulation elements of the DMD 10will be incident at neighboring microlenses, and will be focused atpositions which are separated from the predetermined positions. Forexample, in the example of FIG. 3B, light that should be focused aspixel 48 ₄ is focused as noise 49 at positions of the diode 26 ₄ whichdiffer from the pixel 48 ₄.

As described above, in a case in which there is relative mispositioningbetween the DMD 10 and the microlens array 18, a difference is generatedbetween the output signals P₁, P₂, P₃ and P₄ of the four-part detector26, and the occurrence of an error (offset) can be detected. That is, anoffset in relative positions of the light beams reflected at themicromirrors (modulation elements) of the DMD 10 and the microlensesthat correspond thereto (below referred to as “mispositioning of thebeams”) can be detected. If an offset amount in the X direction is ΔXand an offset amount in the Y direction is ΔY, then, using the values ofthe output signals P₁, P₂, P₃ and P₄, ΔX and ΔY are represented by thefollowing equations. In these equations, k and k′ are constants.

$\begin{matrix}{{{\Delta\; X} = {k\frac{\;{P_{1} + P_{3} - \left( {P_{2} + P_{4}} \right)}}{P_{1} + P_{2} + P_{3} + P_{4}}}}{{\Delta\; Y} = {k^{\prime}\frac{\;{P_{1} + P_{2} - \left( {P_{3} + P_{4}} \right)}}{P_{1} + P_{2} + P_{3} + P_{4}}}}} & {{Equation}\mspace{14mu} 1}\end{matrix}$

Correction of Mispositioning of the Beams

Next, correction of mispositioning of the beams will be described. FIG.5 shows a control routine of the controller 30 when correction iscarried out. An interrupt routine can be implemented in order to carryout detection and correction of mispositioning of the beams with afreely selected timing before commencement of exposure and/or aftercommencement of exposure.

In step 100, the controller 30 lights up the four modulation elements ofthe DMD 10 that correspond to the four pixels which are present atcorner A of the exposure area 46. In step 102, the output signals P₁ toP₄ are acquired from the four-part detector 26. In step 104, the offsetamount in the X direction ΔX and the offset amount in the Y direction ΔYare calculated.

In a subsequent step 106, it is judged whether or not the calculatedoffset amounts ΔX and ΔY are less than pre-specified tolerance amounts.If the offset amounts are not greater than the tolerance amounts, theroutine finishes without carrying out correction of mispositioning ofthe beams. On the other hand, if the offset amounts exceed the toleranceamounts, correction of the mispositioning of the beams is carried out instep 108. In the present embodiment, the DMD 10 is fixedly disposed, sopositional adjustment of the microlens array 18 is carried out, on thebasis of the offset amount ΔX and the offset amount ΔY. Correctionamounts in such a case are −ΔX in the X direction and −ΔY in the Ydirection.

After the positional adjustment has finished, the routine returns tostep 102, new output signals are acquired, and an offset amount ΔX andoffset amount ΔY subsequent to the positional adjustment are calculated.Through step 106, the processing of steps 102 to 108 is repeated untilthe calculated offset amounts ΔX and ΔY are less than or equal to thetolerance amounts. Thus, mispositioning of the beams is eliminated, andthe beams which are incident at the microlenses of the microlens array18 from the respective modulation elements of the DMD 10 are focused atthe predetermined positions of the exposure surface.

Here, instead of repeating steps 102 to 108, it is possible to just moveby −ΔX and −ΔY from a start position, while monitoring contemporaneouspositions of the microlens array 18 with the position detection sensor42.

As described above, in the present embodiment, the four diodes of thefour-part detector are disposed so as to correspond, respectively, to(the images of) the four modulation elements of the DMD. Thus, if thereis relative mispositioning between the DMD and the microlens array, adifference is generated in the output signals of the four-art detector,and an offset of the light beams reflected from the micromirrors of theDMD and the corresponding microlenses (the mispositioning of the beams)can be detected.

Furthermore, in the present embodiment, the mispositioning of the beamsis reduced by the positional correction of the microlens array beingcarried out repeatedly until the mispositioning of the beams is not morethan the tolerance amounts. The mispositioning of the beams may beeradicated by putting the tolerance amounts for the mispositioning ofthe beams infinitesimally close to zero. Hence, the light beams thathave been reflected at the respective micromirrors of the DMD will beproperly incident at the corresponding microlenses, and the DMD imageswill be accurately projected to the focusing surface.

Variant Examples

In the embodiment described above, the four-part detector 26 has beendescribed as being disposed at at least one of the four corners A, B, Cand D of the rectangular exposure area 46. However, as shown in FIG. 6for example, the four-part detector 26 may be provided at two locations,corner A and corner B. By performing measurement at two points,mispositioning in a direction of rotation can also be detected.

For example, if offset amounts of the beams that are detected using thefour-part detector 26 disposed at corner A are ΔX_(A) and ΔY_(A), offsetamounts of beams that are detected using the four-part detector 26disposed at corner B are ΔX_(B) and ΔY_(B), and a separation between Aand B is L, then, in a case in which mispositioning of the beams overthe whole of the exposure area is considered, the offset amount ΔX inthe X direction, the offset amount ΔY in the Y direction and an offsetamount θ_(Z) in the rotational direction are represented by thefollowing equations. Accordingly, in order to eliminate themispositioning of the beams, it is possible to just move the microlensarray 18 by −ΔX, −ΔY, and −θ_(Z) from a start position.

$\begin{matrix}{{{\Delta\; X} = \frac{{\Delta\; X_{A}} + {\Delta\; X_{B}}}{2}}{{\Delta\; Y} = \frac{{\Delta\; Y_{A}} + {\Delta\; Y_{B}}}{2}}{\theta_{Z} = \frac{{\Delta\; Y_{B}} - {\Delta\; Y_{A}}}{L}}} & {{Equation}\mspace{14mu} 2}\end{matrix}$

Alternatively, the four-part detector 26 may be provided at twolocations which are on a diagonal, corner A and corner D, and may beprovided at each of the four corners. By providing the four-partdetector 26 at two corners on a diagonal or at four corners,mispositioning of the beams over the whole exposure area can bedetected, including mispositioning in the rotational direction (angularshifts), shifts in magnification and the like.

Furthermore, in the embodiment described above, an example in which theoffset amount in the X direction and the offset amount in the Ydirection are detected simultaneously has been described. However, theoffset amount in the X direction and the offset amount in the Ydirection may be detected separately. For example, as shown in FIG. 7,it is possible to light up (expose) a total of twelve pixels, two pixelsin the X direction and six pixels in the Y direction, to detect anoffset amount in the X direction. Each diode of the four-part detector26 is assigned to a set of three pixels. In the example of FIG. 7,pixels 48 ₁₁ to 48 ₁₃ are assigned to the diode 26 ₁, pixels 48 ₂₁ to 48₂₃ are allocated to the diode 26 ₂, pixels 48 ₃₁ to 48 ₃₃ are assignedto the diode 26 ₃, and pixels 48 ₄₁ to 48 ₄₃ are assigned to the diode26 ₄

Similarly, it is possible to light up a total of twelve pixels which istwo pixels in the Y direction and six pixels in the X direction todetect an offset amount in the Y direction. If a one-pixel set isassigned to each diode, light amounts for the individual diodes may beinsufficient, and a satisfactory accuracy of detection may not beobtained. In such cases, detection accuracy can be improved by theabove-described method of increasing the number of pixels that are litup at least in the direction in which an offset amount is to bedetected. Incidentally, a two-part detector may be used in such a case.

Further, in the embodiment described above, an example in which thefour-part detector is disposed at a corner of the exposure area when thestage is disposed at the reference position has been described. However,as shown by the broken lines in FIG. 8, the four-part detector 26 may bedisposed outside the exposure area 46 when the stage 24 is disposed atthe reference position.

During detection of mispositioning of the beams, the four-part detector26 is moved together with the stage 24, and the four-part detector 26 isdisposed at a corner of the exposure area 46, as shown by the solidlines in FIG. 8. Thus, by making a structure capable of inserting andwithdrawing the four-part detector 26, it is possible to respond toshrinking of the exposure area, lengthening of a cycle time and thelike. However, it is necessary to move the four-part detector 26 suchthat gaps between the diodes do not overlap with pixels that are lit up,and it is necessary for the stage to be movable with a repeatability oftens of microns.

Alternatively, dummy pixels which are not employed for exposure may bedisposed at one corner of the exposure area. Hence, mispositioning ofthe beams can be detected continuously.

Further still, in the embodiment described above, an example in whichthe position of the microlens array is adjusted to correctmispositioning of the beams has been described. However, instead of themicrolens array, the position of the magnification adjustment lens maybe adjusted. Moreover, the position of the DMD may be adjusted. Forexample, if, of these structural members, the position of a member whosesensitivity with respect to shifting of the optical axis is lower isadjusted, such that a mispositioning of 10 μm can be corrected with anoptical axis movement of 2 μm, optical axis adjustment is easier.Alternatively, mispositioning of the beams may also be corrected for byinserting a parallel flat plate at the light incidence side of themicrolens array, and altering inclination of this parallel flat plate.

Further yet, in the embodiment described above, an example which usesthe four-art detector has been described. However, instead of thefour-part detector, a two-dimensional CCD (charge coupled device),phototransistors or the like may be divided between regions andemployed.

Further again, in the embodiment described above, an example in which atrimming mechanism which utilizes piezoelectric elements is employed asthe trimming mechanism which adjusts the position of a lens or the likehas been described. However, other trimming mechanisms may be employed.For example, other than structures which push an object of movement fromthree directions with piezoelectric devices such as piezo elements andthe like, it is possible to employ a mechanism which uses a Peltierelement and thermistors and which controls temperature to controlextension/compression amounts of a retaining member for an object ofmovement, a mechanical mechanism which scales down movement amounts bycombining an electric motor with a speed reduction mechanism, a cam orthe like, or the like.

According to an exposure device of the present invention, there is aneffect that it is possible to accurately project an image of a spatiallight modulation device at a focusing plane.

1. A drawing device comprising: a spatial modulation device including aplurality of unit elements arranged two-dimensionally, and each beingfor modulating an incident beam in accordance with control signals; amicrolens array including microlenses arranged to correspond to theplurality of unit elements and adapted to respectively condense beamsmodulated by the unit elements; a displacement detection section fordetecting displacement of a relative position of at least one of theplurality of unit elements and at least one of the plurality ofmicrolenses corresponding to the at least one unit element from apredetermined relative position; and a mechanism which adjusts arelative position of the spatial modulation device and the microlensarray on the basis of the detected displacement.
 2. A drawing deviceaccording to claim 1, wherein the displacement is in a directionperpendicular to a beam axis.
 3. A drawing device comprising: a spatialmodulation device including a plurality of unit elements arrangedtwo-dimensionally, and each being for modulating an incident bean-i inaccordance with control signals; a microlens array including microlensesarranged to correspond to the plurality of unit elements and adapted torespectively condense beams modulated by the unit elements; and amechanism which adjusts a relative position of the spatial modulationdevice and the microlens array so as to be in a predetermined relativeposition.
 4. A drawing device comprising: a spatial modulation deviceincluding a plurality of unit elements arranged two-dimensionally, andeach being for modulating an incident beam in accordance with controlsignals; a microlens array including microlenses arranged to correspondto the plurality of unit elements and adapted to respectively condensebeams modulated by the unit elements; and a mechanism which adjusts arelative position of the spatial modulation device and the microlensarray to beam axis.
 5. A drawing device according to any one of claims1, 3, or 4, wherein the unit elements are micromirrors.
 6. A drawingdevice according to any one of claims 1, 3, or 4, wherein the unitelements correspond one-to-one to the microlenses.
 7. A method fordrawing by modulating a beam which is incident at a plurality of unitelements which are arranged two-dimensionally, and condensing themodulated beam with a plurality of microlenses which are arranged tocorrespond to the plurality of unit elements, the method comprising:detecting displacement of a relative position from a predeterminedrelative position of at least one of the plurality of unit elements andat least one of the plurality of microlenses corresponding to the atleast one of the plurality of unit elements, and; fine adjusting atleast one of a spatial relative position of the plurality of unitelements and the plurality of microlenses, and a position of theplurality of unit elements and the plurality of microlenses relative toa beam axis, on the basis of the detected displacement.
 8. A method fordrawing according to claim 7, wherein the detecting displacement isperformed on the basis of the intensity of the beam passed through amicrolens.
 9. A method for drawing according to claim 7, wherein thedetecting displacement is performed on the basis of a balance of theintensity of beams passed through at least two microlenses.